Log eight everyday factors each day, plus how your mood actually felt. The tracker calculates a predicted score from the factors, weighted by how strongly research links each one to depression, and compares it with your real mood over time.
| Variable | Measures | Expected | Weight | Your r | Match? |
|---|
r is the correlation between that factor and your actual Dep score, from β1 to +1. Results start after 7 days but are marked βearly readβ until 30 days, since a single stressful week can flip a sign.
In statistics, "actual" means what was measured, and "predicted" means what the formula calculates.
Depression is defined by how a person feels, so your own rating is the measurement and the formula is the estimate we test against it. The gap between them is u, everything the formula misses.
r is the correlation coefficient. It shows how closely two things move together, from β1 to +1:
Example: Sleep has r = β0.45. On days after more sleep, your Dep score tends to be lower. That's a moderate link, and it matches Sleep's expected (β) sign.
Why it matters: r checks whether the formula fits you. If a factor's r matches its expected sign, that factor seems to matter for you. If it's near 0 or the opposite sign, it may matter less for you than for people in general, or something else is going on. r shows a link, not a cause, and it becomes reliable after about 30 days.
The Patient Health Questionnaire-8 is a short questionnaire doctors and researchers use to measure depression. Each of its 8 questions matches a core depression symptom, like low mood, poor sleep, low energy and trouble concentrating, and is scored from 0 to 3, for a total of 0β24. It's the widely used PHQ-9 without its final question.
Why researchers use it: it takes about 2 minutes, is free to use and has been tested in many large studies. Because the questions never change, scores can be compared week to week and between people. A score of 10 or more is the usual sign of clinically significant depression.
| Score | Severity |
|---|---|
| 0β4 | None or minimal |
| 5β9 | Mild |
| 10β14 | Moderate |
| 15β19 | Moderately severe |
| 20β24 | Severe |
Kibbywell asks once a week. Comparing PHQ-8 scores with your daily Dep ratings shows whether the quick daily slider tracks the real picture. It's a screening tool, not a diagnosis. A high score is a good reason to talk to a doctor.
Why log actual mood separately? If Dep were only calculated, the formula would always be "right" and there'd be nothing to test. Comparing the prediction with how you really felt is how you learn which factors matter for you. Keep in mind it can run both ways: a low day can cause poor sleep, not only the reverse.
Read results with care. Mood can color your ratings: on a low day, nutrition, social time and gratitude may all feel worse than they were, which makes the links look stronger. Factors also move together (weekends often bring more sleep and less stress), so the tracker can't always tell which one helped. Treat results as patterns to notice, not proof.
Your days are saved in this browser. Download the spreadsheet now and then to keep your own copy. Each saved day is also emailed to chaukibby@gmail.com as a record.
About 2 minutes. Over the last 2 weeks, how often have you been bothered by any of the following problems?